Two-way handheld or mobile radio users are familiar and accustomed to rotary controls. Such controls are susceptible to damage during impact, due to inadvertent drops or mishandling. Such controls on a radio can include for example volume control, channel selection, and squelch control among others. Since products are generally decreasing in size, traditional rotary controls tend to be mounted in close proximity to other controls on a given product. Thus, damage to rotary controls is exacerbated by requirements for an appropriately or ergonomically sized control at the user interface as well as by use of miniaturized shafts used to actuate a physical switch component. Further note that the force of impact on the external surface of such rotary controls or knobs often gets transmitted to the switching element within a radio housing resulting in physical damage to the switching element and possibly other contact points within the radio.
Another issue confronting rotary controls on a control surface of a product involves inadvertent or unintentional actuation of controls. The grip area accessible by users for these rotary controls traditionally extends to the control surface of a product. This results in an increased risk of inadvertent actuation as the operation of one control might cause a user's rotating fingers to accidentally adjust an adjacent control. End users expect rotary controls to be spaced with appropriate lateral clearances to adjacent controls as embodied in previous, larger, products to suit the size of a user's hands and fingers during operation. Although various attempts have been made to reduce the effects of impacts to switching elements in radios, such attempts fail to reduce the risk of inadvertent actuation. In some instances a boss is used, but the boss protrudes into a core of the knob.